Septic shock can be defined as a spectrum of clinical conditions caused by the immune response of a host to infection or trauma characterized by systemic inflammation and coagulation (Mesters R M, et al. Increase of plasminogen activator inhibitor levels predicts outcome of leukocytopenic patients and sepsis. Thromb Haemost. 1996a; 75: 902-907; Wheeler A P and Bernard G R. Treating patients with severe sepsis. N Engl J Med 340: 207-214 (1999)). Conditions range from a systemic inflammatory response to organ dysfunction to multiple organ failure, and ultimately death. In elderly, immunocompromised, and critically ill patients, septic shock is a major cause of morbidity and mortality in intensive care units worldwide (Friedman G, et al. Has the mortality of septic shock changed with time? Crit Care Med. 26:2078-2086 (1998)). In the United States, septic shock is the leading cause of death in noncoronary intensive care unit (ICU) patients (Sands K E, et al. Epidemiology of sepsis syndrome in 8 academic medical centers. JAMA 278: 234-240 (1997)). Additionally, 1998 data from the Centers for Disease Control show that septic shock is the 11th leading cause of death overall (National Vital Statistics Report, 2000).
Flavonoids or bioflavonoids encompass a ubiquitous group of polyphenolic substances that are present in most plants, concentrated in seeds, fruit skin or peel, bark, and flowers. Various classes of flavonoids include the following: flavanols, flavanones, flavones (2-phenylchrmones), flavan-3-ols (catechins), anthocyanins, and isoflavones (3-phenylchrmones). Baicalein, baicalin, and wogonin (shown below) are known bioactive flavonoids of Scutellaria baicalensis GEORGI. In recent studies, baicalein, baicalin, and wogonin have been reported to show anti-inflammatory [Bao, Q L et al. The flavonoid baicalin exhibits anti-inflammatory activity by binding to chemokines. Immunopharmacology. 49: 295-306 (2000); Wakabayashi I and Yasui K Wogonin inhibits inducible prostaglandin E2 production in macrophages. Eur J Pharmacol. 406: 477481 (2000); Kimura et al. Effects of baicalein isolated from Scutellaria baicalensis on interleukin 1 β- and tumor necrosis factor α-induced adhesion molecule expression in cultured human umbilical vein endothelial cells. J Ethnopharmacol. 57: 63-67 (1997); and Lin C C and Shieh D E The anti-inflammatory activity of Scutellaria rivularis extracts and its active components, baicalin, baicalein and wogonin. Am J Chin Med. 24: 31-36 (1996)], anti-allergic (Kyo et al. Baicalin and baicalein, constituents of an important medicinal plant, inhibit intracellular Ca2+ elevation by reducing phospholipase C activity in C6 rat glioma cells. J. Pharm Pharmacol. 50: 1179-1182 (1998); Gao et al. Free radical scavenging and antioxidant activities of flavonoids extracted from the radix of Scutellaria baicalensis Georgi. Biochemica et Biophysica Acta B. 1472: 643-650 (1999); Gabrielska J Antioxidant activity of flavones from Scutellaria baicalensis in lecithin liposomes. J Biosci. 52: 817-823 (1997)], antioxidant [Shieh et al. Antioxidant and free radical scavenging effects of baicalein, baicalin, and wogonin. Anticancer Res. 20: 2861-2865 (2000)], and anticancer activities [Ikemoto S et al. Antitumor effects of Scutellariae Radix and its components baicalein, baicalin, and wogonin on bladder cancer cell lines. Urology 55: 951-955 (2000); Chan F L et al. Induction of apoptosis in prostate cancer cell lines by flavonoid, baicalin. Cancer Lett. (2000)]. Moreover, baicalin has been shown to possess antiviral activity [Nagai T et al. Mode of action of the anti-influenza virus activity of plant flavonoid, 5,7,4′-trihydroxy-8-methoxyflavone, from the roots of Scutellaria baicalensis. Antiviral Res. 26: 11-25 (1995); Nagai T et al. Mode of action of the anti-influenza virus activity of plant flavonoid, 5,7,4′-trihydroxy-8-methoxyflavone, from the roots of Scutellaria baicalensis and enhancement of its activity by drug delivery system. Antiviral Res. 30: A1-A62 (1995); and Kitamura K et al. Baicalin, an inhibitor of HIV-1 production in vitro. Antiviral Res. 37: 131-140 (1998)], and baicalein has been shown to produce a hypotensive effect (Takizawa et al. Prostaglandin I2 contributes to the vasodepressor effect of baicalein in hypertensive rats. Hypertension 31: 866-871(1998) and Chen Z Y et al. Endothelium-dependent contraction and direct relaxation induced by baicalein in rat mesenteric artery. Eur J Pharmacol. 374:41-47 (1999)]. More recently, baicalein has been implicated in the inhibition of expression of adhesion molecules induced by cytokines in human umbilical vein endothelial cells [Ikemoto, S et al. Antitumor effects of Scutellariae radix and its components baicalein, baicalin, and wogonin on bladder cancer cell lines. Urology. 55: 951-955 (2002); Middleton, E J and Kandaswani C. Effects of flavonoids on immune and inflammatory cell functions. Biochem. Pharmacol. 43: 1167-1179 (1992)].

Current therapies for the treatment of septic shock include antibiotics, vasoconstrictors, steroids, and fluid supplementation to maintain the circulation volume; however, in many cases, these therapies have been deemed inefficient (Barron R L. Pathophysiology of septic shock and implications for therapy. Clin. Pharm. 12: 829-845 (1993)). It is desirable to provide compounds useful for the prevention or treatment of septic shock.
During the course of sepsis, nitric oxide (NO) is produced. Its metabolites impair normal vascular reactivity, in conjunction with elevated endotoxin levels. Inhibitors of NO synthase restore blood pressure, lower the cardiac index and increase pulmonary and systemic vascular resistance. Selective NOS inhibitors targeted against iNOS may prove to be beneficial. A small study with an inhibitor of NOS action, namely methylene blue, which inhibits the associated guanylyl cyclase enzyme, has indicated beneficial effects versus the cardiovascular parameters described above in patients with septic shock (Preiser, J C, Lejeune P, Roman A, et al. Methylene blue administration in septic shock: a clinical trial. Crit. Care Med., 23: 259-64(1995); Gachot B, Bedos J P, Veber B, et al. Short term effects of methylene blue on hemodynamics and gas exchange in humans with septic shock, Intensive Care Med 21:1027-31; Vincent, J L, Sun Q, Dubois, M-J, Clinical Trials of Immunomodulatory Therapies in Severe Sepsis and Septic Shock, CID, 34: 1084-1093 (2002)).
TNF-α (tissue necrosis factor), a cytokine that plays a critical role in eliciting the body's inflammatory response and is present in abnormally high levels in the joints of individuals suffering from rheumatoid arthritis, has been implicated as an immune modulator in the immune system. Inhibitors of TNF-α have been shown to halt the progression of cartilage destruction and relieve the symptoms of severe arthritis. Approximately 30% of moderate to severe arthritic patients are not responsive to these treatments (Feldman M, Maini R N, Discovery of TNF-α as a therapeutic target in rheumatoid arthritis: preclinical and clinical studies. Joint Bone Spine 2002, 69, 12-18; Lipsky P E, et al. Infliximab and methotrexate in the treatment of rheumatoid arthritis. N. Engl. J. Med. 2000, 343 1954-1602). Animal studies in association with studies conducted in humans indicate a potential role for TNF modulation in Crohn's disease, ulcerative colitis, insulin resistance, multiple sclerosis, multiple organ failure, pulmonary fibrosis, and atherosclerosis (Newton R C, Decicco C P, Therapeutic potential and strategies for inhibiting tumor necrosis factor-a. J. Med. Chem. 1999, 42, 2295-2314).
Aerobic organisms, which derive their energy from the reduction of oxygen, are susceptible to the damaging actions of the small amounts of O2—, OH and H2O2 that inevitably form during the metabolism of oxygen, especially in the reduction of oxygen by the electron transfer system of mitochondria. These three species, together with unstable intermediates in the peroxidation of lipids, are referred to as Reactive Oxygen Species (ROS). Many diseases such as, but not limited to, Alzheimer's Disease, Parkinson's disease, aging, cancer, myocardial infarction, atherosclerosis, autoimmune diseases, radiation injury, emphysema, sunburn, and joint disease (a. Everything cytokine & beyond, Cytokines Mini-Reviews, Chapter: Reactive Oxygen Species (ROS), Copyright 2003 ©R&D Systems; b. Channon K M, Guzik T J, Mechanisms of superoxide production in human blood vessels: relationship to endothelial dysfunction, clinical and genetic risk factors. J. Physiol. Pharmacol. 2002, 53(4), 515-524; c. Henrotin, Y E et al. The role of reactive oxygen species in homeostasis and degradation of cartilage. OsteoArthritis and Cartilage 2003, 11, 747-755; d. Arzimanoglou A et al. Epilepsy and neuroprotection: An illustrated review article. Epileptic Disord 2002, 3, 173-82; e. Seidman M D et al., Biologic activity of mitochondrial metabolites on aging and age-related hearing loss. Am J Otol 2000, 21(2):161-7.) are linked to damage from ROS as a result of an imbalance between radical-generating and radical-scavenging systems—a condition called oxidative stress. The discovery by McCord and Fridovich (McCord, J. M. & I. Fridovich J. Biol. Chem. 1969, 244:6049) of the superoxide dismutase (SOD) activity of erythrocuprein, together with the finding that almost all mammalian cells contain SOD, suggests a physiological role of at least the central ROS, superoxide.